This invention relates generally to improvements in the structure of releasable stop assembly mechanisms for use with bidirectionally swinging doors, and particularly to a stop assembly mechanism constructed and arranged to provide an improved and unique type of compound operation or movement of the stop during depression.
To facilitate the disclosure, the stop assembly of this invention is illustrated and described herein in conjunction with doors in hospitals, nursing homes, and like areas. However, it should be understood that the present invention may find use in other application as well.
Heretofore, emergency release door stop assembly devices for bidirectionally swinging doors have been provided as shown for example in U.S. Pat. Nos. 2,889,571; 3,172,168; and 3,946,460. Generally speaking, these stop mechanisms are arranged to block movement of the door in other than the direction of normal opening, but can be selectively actuated, such that the door is released for opening in the opposite direction of its normaly use, for example during an emergency situation. This feature is particularly useful in hospitals, nursing homes, or the like where it may become necessary to rescue a patient who is behind a locked, inwardly opening door. In such situations, rapid rescue is generally desired, and thus taking the time to locate a suitable key or other release device for the lock mechanism is generally far less preferable than provision of a releasable stop for permitting the door to be opened in the opposite direction, i.e. outwardly. Also the use of such stops is less expensive than locks which include outside release mechanisms. Moreover, in many cases even though the lock may be released, opening of the door in its normal direction may be precluded as the patient may have collapsed in such a way as to block normal door movement.
The prior art emergency release door stops taught in the first two of the above-referenced patents generally include a stop element which was pivotally mounted and which protruded from the door frame so as to engage the edge of the door, limiting operation thereof to a first or normal direction. In order to open the door in an opposite direction, the stop element must be manually pivoted to a nonblocking position. In service, however, these pivotally mounted stops have proven disadvantageous from a number of standpoints. Initially, it should be recognized that such emergency use of the stop is relatively infrequent, such that the elements which provide the pivotal mounting tend to corrode or bind in place, resulting in the danger that they may malfunction when required. Moreover, in such places as hospitals, where these releasable stops are often used, washing of the doorways takes place relatively frequently, whereupon foreign materials such as soap, water, or other residue from washing may accumulate in the pivoting mechanism or the mechanism may rust or corrode thereby precluding proper operation thereof.
A further disadvantage of these prior art stops, was the difficulty of initially positioning the stop to provide a firm rattle-free disposition of the door, when the latching mechanism of the door was engaged. Even after proper initial installation in service, misalignment may later result from such factors as wear of the stop member or warping of the door, which could result in a door that rattled in the closed position.
The releasable door stop assembly disclosed in the latter of the above-referenced patents, U.S. Pat. No. 3,946,460 avoids these disadvantages. More specifically, in the embodiment therein disclosed, the pivotal mounted stop was replaced by a free floating, spring biased stop member. Further, the stop included an adjustably mounted abutment surface member which may be adjusted toward and away from the door, as necessary to assure both initial and continued proper alignment. While the releasable door stop structure as shown in said U.S. Pat. No. 3,946,460, has proven particularly reliable and effective in use, the present invention provides substantial improvements in this structure, primarily in the manner in which spring biasing is achieved which results in ease and safety of operation, as more fully described hereinbelow.
Accordingly, it is a general object of this invention to provide a new and improved releasable door stop assembly for bidirectionally swinging doors, and more specifically, to provide a releasable door stop assembly of the type described which is responsive to application of a surprisingly low amount of force for initiating its releasing action. Still another object of this invention is to provide an improved releasable door stop of the type described which when depressed, includes a surface which is substantially flush with the door frame, thereby eliminating any danger that the operator's fingers may be caught or pinched.
Briefly, the releasable door stop assembly of this invention includes a housing adapted to reside in the mortise of a door frame, and a stop member mounted for compound movement within the housing. A face plate includes an aperture through which a portion of the stop member normally protrudes. Biasing means in the form of a leaf spring, or the equivalent, which engages the free floating stop member initially only proximate a forward portion thereof. Accordingly, upon manual operation, little if any force opposes depression of the rearward portion of the stop member, which after being bottomed with respect to the housing, can be rocked forward against the biasing action of the spring to cause a surface segment of said stop to be disposed flush with the face plate, thereby permitting the door to swing past the stop without the danger of pinching the operator's fingers. The employment of a leaf spring mounted to the casing and separate from the stop, as opposed to the pair of coiled springs illustrated in U.S. Pat. No. 3,946,460 results in certain unexpected and surprising advantages. Due to the cantilevered nature of the spring and the long moment arm which results, the stop means is responsive to relatively small pressure or forces. Initially, the rear portion will move linearly inward, against little if any spring force, since the spring engages the forward section of the stop member. Subsequently, when the stop member is rocked forward, the spring force can easily be overcome due to the relatively long moment arm resulting from the fixed mounting of one end of the spring. As a further feature, the stop and the spring means are not interconnected, accordingly, the stop member is free to move or slide relative to the spring. Thus, when the stop is rocked forward, the spring force acting only on the forward portion, will produce relative movement of the stop rearwardly and upwardly, which positions the inclined or rear surface of the stop member at the proximate level of the face plate aperture to assure that the operator's fingers are not pinched as the door moves past the stop.
Other objects, features and advantages of the invention will be more fully appreciated upon consideration of the following detailed description of the invention and its mode of operation, together with the accompanying drawings.